A writer who said he was set to travel on the doomed Titan submersible said OceanGate CEO Stockton Rush told him that for the vessel's hull, the company used cut-price Boeing carbon fiber that was past its airplane shelf life.

The stunning claim came in a series of articles by Travel Weekly's editor in chief, Arnie Weissmann, who this week chronicled his experiences with the deep-sea-diving company.

Weissmann wrote that he was due to board the Titan to view the Titanic in May but the trip was stopped by weather. In fact, just a couple of weeks stood between his would-be voyage and the trip that ended in tragedy this week when the vessel imploded, killing all five on board, he wrote.

In general, he said, he was impressed by "what appeared to be a risk-averse operation."

But one thing concerned him, he wrote.

Rush told Weissmann that "he had gotten the carbon fiber used to make the Titan at a big discount from Boeing because it was past its shelf life for use in airplanes," Weissmann wrote.

In his recollection, he asked Rush whether that was a problem, but he said he was told that the shelf-life dates "were set far before they had to be."

Both OceanGate and Boeing declined to comment on Weissmann's claims. Insider was unable to independently verify the source of the Titan's carbon fiber.

OceanGate's website previously claimed that the vessel was designed and engineered "in collaboration" with Boeing.

Boeing has denied any involvement in the design of the Titan.

Much remains unknown about the circumstances of the disaster, including what could have caused the vessel to implode. The US Coast Guard said Thursday that debris found at the scene was "consistent with catastrophic loss of the pressure chamber."

The Titan's experimental carbon-fiber hull has become a subject of discussion since the vessel went missing.

Rush previously touted the cost-saving benefits of carbon fiber versus the standard titanium and claimed in a 2021 presentation that "carbon fiber is three times better on a strength-to-buoyancy basis than titanium."

"And underwater, that's what you care about," he added.

A 2017 CompositesWorld report said the initial carbon-fiber hull design was prepared on just a six-week deadline, though GeekWire reported the vessel was rebuilt later.

Before the tragic trip, Rush publicly discussed taking risks to pursue what he called "innovation," saying in 2021 that he knew he had "broken some rules" by using a carbon-fiber hull for the vessel.